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Oil:

Oils are consisted with vegetable or animal oils until the years 1900. The best vegetable lubrication oil is the castor oil.

Currently oils are made up basic mineral hydrocarbons which determine the essence of their viscosity. Radical COOH confers their consistency because they are fixed perpendicularly at surfaces (force of adsorption which are defined by ionic attractions). The additives take part in the improvement of the antioxydant characteristics, anti-foamer and temperature.

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greases :

Greases are soap gel containing oil like sponges. The consistency of a grease is due to the texture of gel and the relative proportions between gel and oil. The types of greases are carried out on the basis of a limited number of combinations between the fatty acids and metals like calcium, sodium, potassium...

To summarize a type of grease is defined by specifying its fatty acid, its metal and its dispersant (phenol, acid, alcohol but more generally glycerin).

The quality of a "sponge-soap" consists in releasing its oil too slowly neither nor too quickly.

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